Conventionally, there are known backlight devices that include a connector member connected electrically to a light source. FIGS. 18 to 21 are diagrams showing the structure of a connector member of one example of the conventional backlight devices. As shown in FIGS. 18 and 19, the example of the conventional backlight devices includes: a light source 501 that has a cap portion 501a at its end portion; a connector member 502 that is electrically connected to the cap portion 501a of the light source 501; and a support board 503 to which the connector member 502 is attached. The connector member 502 includes a pair of holding plates 502a that hold the cap portion 501a of the light source 501 from both sides.
In the example of the conventional backlight devices, when the light source 501 is fitted into the connector member 502, as shown in FIG. 20, the pair of holding plates 502a of the connector member 502 is pushed and extended outward by the cap portion 501a of the light source 501 such that the light source 501 is placed into a predetermined position of the connector member 502. In other words, a predetermined force is applied to the light source 501, and simultaneously the light source 501 is positioned with respect to the connector member 502.
In the example of the conventional backlight devices, even if the light source 501 is not displaced with respect to the connector member 502 (normal state), when the light source 501 is fitted into the connector member 502, a force (reaction force) exerted by the pushing and expanding of the pair of holding plates 502a by the cap portion 501a of the light source 501 is applied from the connector member 502 to the light source 501. Hence, when the light source 501 is fitted into the connector member 502 with the light source 501 displaced with respect to the connector member 502 (emergency state), even if the force (reaction force) larger than the normal state is applied from the connector member 502 to the light source 501, it is difficult to determine whether or not the force (reaction force) applied from the connector member 502 is larger than the normal state. In other words, it is difficult to determine whether or not the light source 501 is displaced with respect to the connector member 502. Therefore, when the light source 501 is fitted into the connector member 502 with the light source 501 displaced with respect to the connector member 502, it is likely that, as shown in FIG. 21, the holding plates 502a are plastically deformed and are thus held extended outward. In this case, the cap portion 501a of the light source 501 disadvantageously fails to be connected satisfactorily and electrically to the connector member 502.
Conventionally, there are proposed connector members that can solve the disadvantage described above (for example, see patent document 1).
In this patent document 1, there is disclosed a cold cathode tube connector (connector member) that has: a housing including a contact (contact portion) connected electrically to an electrode wire (contact portion) provided in an end portion of the cold cathode tube (light source); and a cover attached to the housing. The contact of the housing is provided with a pair of movable parts that holds the electrode wire of the cold cathode tube from both sides. The pair of movable parts is spaced apart from each other such that the space therebetween is larger than the diameter of the electrode wire of the cold cathode tube. The cover is provided with actuating protrusions that hold the pair of movable parts from both sides.
When the cold cathode tube is attached to the cold cathode tube connector, the electrode wire of the cold cathode tube is arranged between the pair of movable parts of the housing. Here, since the pair of movable parts is spaced apart from each other such that the space is larger than the diameter of the electrode wire of the cold cathode tube, the electrode wire of the cold cathode tube is arranged between the pair of movable parts without making contact with the pair of movable parts. Thereafter, when the cover is attached to the housing, the actuating protrusions on the cover hold the pair of movable parts of the housing from both sides, and the pair of movable parts of the connector member is electrically connected to the electrode wire of the cold cathode tube.
In patent document 1 described above, when the cold cathode tube is arranged between the pair of movable parts, no force is applied to the cold cathode tube with the cold cathode tube not being displaced with respect to the housing (normal state). Hence, when a force (reaction force) is applied from the housing or the like to the cold cathode tube so that the cold cathode tube is arranged between the pair of movable parts with the cold cathode tube displaced with respect to the housing (emergency state), it is possible to determine that the cold cathode tube is displaced with respect to the housing.    Patent document 1: JP-A-2007-165208